<template>
  <div class="app-container">
    课程列表
    <!--查询表单-->
    <el-form :inline="true" class="demo-form-inline">
      <el-form-item>
        <el-input v-model="courseQuery.title" placeholder="课程名称" />
      </el-form-item>

      <el-form-item>
        <el-select
          v-model="courseQuery.subjectParentId"
          placeholder="一级分类"
          @change="subjectLevelOneChanged">
          <el-option
            v-for="subject in subjectOneList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
      </el-form-item>
      <el-form-item>
        <!-- 二级分类 -->
        <el-select v-model="courseQuery.subjectId" placeholder="二级分类">
          <el-option
            v-for="subject in subjectTwoList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
      </el-form-item>

      <el-button type="primary" icon="el-icon-search" @click="getList()">查询</el-button>
      <el-button type="default" @click="resetData()">清空</el-button>
    </el-form>

    <!-- 表格 -->
    <el-table :data="list" border fit highlight-current-row>
      <el-table-column label="序号" width="70" align="center">
        <template slot-scope="scope">{{ (page - 1) * limit + scope.$index + 1 }}</template>
      </el-table-column>

      <el-table-column prop="title" label="课程名称" />

      <el-table-column label="课程状态" width="80">
        <template slot-scope="scope">{{ scope.row.status==='Normal'?'已发布':'未发布' }}</template>
      </el-table-column>

      <el-table-column prop="lessonNum" label="课时数" width="80" />

      <el-table-column prop="gmtCreate" label="添加时间" width="160" />

      <el-table-column prop="viewCount" label="浏览数量" width="60" />

      <el-table-column label="操作" width="200" align="center">
        <template slot-scope="scope">
          <router-link :to="'/course/info/'+scope.row.id">
            <el-button type="primary" size="mini" icon="el-icon-edit" title="编辑课程基本信息" />
          </router-link>
          <el-button
            type="danger"
            size="mini"
            icon="el-icon-delete"
            @click="removeCourseById(scope.row.id)"
            title="删除课程信息"
          />
        </template>
      </el-table-column>
    </el-table>

    <!-- 分页组件 -->
    <el-pagination
      background
      @current-change="getList"
      :current-page="page"
      :page-size="limit"
      :total="total"
      style="padding: 30px 0; text-align: center;"
      layout="total, prev, pager, next, jumper">
    </el-pagination>
  </div>
</template>

<script>
  import course from "@/api/edu/course";
  import subject from "@/api/edu/subject";

  export default {
    name: "list",
    data() {
      //定义变量和初始值
      return {
        list: null, //查询之后接口返回集合
        page: 1, //当前页
        limit: 5, //每页记录数
        total: 0, //总记录数
        courseQuery: {}, //条件封装对象
        subjectOneList: [], //一级分类
        subjectTwoList: [] //二级分类
      };
    },
    created() {
      //页面渲染之前执行，一般调用methods定义的方法
      //调用
      this.getList();
      this.getOneSubjectList();
    },
    methods: {
      //创建具体的方法，调用teacher.js定义的方法
      //讲师列表的方法
      getList(page = 1) {
        this.page = page;
        course.pageCourse(this.page, this.limit, this.courseQuery)
          .then(response => {
            //请求成功
            //response接口返回的数据
            this.list = response.data.rows;
            this.total = response.data.total;
           })
          .catch(error => {
            console.log(error)
          });
      },

      resetData() {
        //清空的方法
        //表单输入项数据清空
        this.courseQuery = {};
        //查询所有讲师数据
        this.getAllCourses();
      },

      removeCourseById(courseId) {
        this.$confirm("是否要删除该课程?", "提示", {
          confirmButtonText: "确定",
          cancelButtonText: "取消",
          type: "warning"
        })
          .then(() => {
            course.removeCourseById(courseId).then(res => {

              this.$message({
                type: "success",
                message: "删除课程成功!"
              });
              this.getList();
            })
            .catch(error => {
              console.log(error)
            });
          })
          .catch(() => {
            return;
          });
      },

      subjectLevelOneChanged(value) {
        //value就是一级分类id值
        //遍历所有的分类，包含一级和二级
        for (let i = 0; i < this.subjectOneList.length; i++) {
          //每个一级分类
          let oneSubject = this.subjectOneList[i];
          //判断：所有一级分类id 和 点击一级分类id是否一样
          if (value === oneSubject.id) {
            //从一级分类获取里面所有的二级分类
            this.subjectTwoList = oneSubject.children;
            //把二级分类id值清空
            this.courseInfo.subjectId = "";
          }
        }
      },
      // 获取所有一级分类
      getOneSubjectList() {
        subject.getAllSubjectList().then(res => {
          this.subjectOneList = res.data.items;
        });
      },

    }
  }
</script>

<style scoped>

</style>
